Dry sterilizer cabinet



Dec. 6, 1949 L. FISHER DRY STERILIZER CABINET Filed April 26. 1948 INVENTOR. LEO/mm: FISHEQ BY M 0 ATTO ulo zk RNE Y Patented Dec. 6, 1949 DRY STERILIZER CABINET Leonard Fisher, San Francisco, Calif., assignor to Ralph S. Fisher, San Francisco, Calif.

Application April 26, 1948, Serial No. 23,182

3 Claims.

This invention relates to a portable dry-sterilizer cabinet.

The sterilization, or disinfection at least, of various items used in connection with the practice of medicine, those used by barbers, etc., is widely practiced. Probably the most common devices make use of steam, boiling water, or a fluid containing a disinfecting and/or sterilizing agent. For example, barbers and beauty operators are wont to store combs not in use in a container of such fluid, in such manner that the combs are substantially immersed in the fluid. Not all the items a barber uses, however, are susceptible to this type of treatment. For example, the storage of a brush in any aqueous liquid renders the bristles so soft as to be substantially useless; electrically operated devices such as clippers and cutters obviously cannot be immersed in a liquid or subjected to steam; therefore, wet sterilizers are not satisfactory in many fields where sterilization is highly desirable.

The use of steam or hot water is not generally practiced by barbers, but is used by doctors and dentists in sterilizing forceps, scalpels and other manipulative devices which they use. Such sterilizers require attention for they must be supplied with water; to be convenient to use, manipulative adjuncts, such as pedals and the like, to open and close the cover in order to avoid burning the operators hand, must be provided.

Dry sterilizers, on the other hand, have not been particularly suitable, since they are slow in operation and uncertain of results as applied to certain items such as hairbrushes, which require a considerable penetrative ability of the agent utilized. Thus, a brush has been found not to have been satisfactorily disinfected from B. anthracis one and one-half hours after having been placed in a common type of dry sterilizer using formaldehyde. Formaldehyde vapor appears to have very little natural penetrative ability; it does not get into the tiny crevices, though it is quite able to kill the germ when it comes in contact with it.

A major object of my invention is to provide an easy-to-use cabinet, including apparatus capable of vaporizing such a fumigant as formaldehyde, for sterilizinfg or disinfecting such articles as combs, brushes, razors, clippers, surgical instruments, etc., in a relatively short period of time.

A specific object of my invention is to provide a sterilizing cabinet containing a fumigant vaporizer and a circulating fan both controlled by the operation of the access door, so as to minimize loss of the active agent.

Other objects will appear in the course of the description.

In the drawing, Figure 1 is an elevation of the cabinet.

Figure 2 is a vertical section substantially on a center line of the cabinet.

Figure 3 is a horizontal section on line 3-3 of Figure 1.

Figure 4 is a detail section on line 4-4 of Figure 1.

The cabinet includes the bottom III, the top I l and sides i2, going to make up a complete enclosure. Any desired plurality of shelves I3 is provided, in this instance, two. These shelves are of an area corresponding to. but less than, the cross sectional dimensions of the cabinet, and are spaced from the walls at all sides by their support on the pins I4, as is best shown in Figure 4. The shelves further include a multiplicity of apertures 15 to permit circulation of the cabinet atmosphere.

Channel members iii are provided at the sides of the opening, which is preferably on one of the wider sides of the cabinet, and a door ll slides vertically in these channels, operated by a knob Hi.

In a lower corner of the cabinet, which is generally of a rectangular cross section vertically, is located the fumigant vaporizer referred by the reference character l9. As shown in Figure 2 in section, this includes a shelf 20 to support a fumigant tablet 2|, and an electric lamp or other electric heater 22. The container, or vaporizer l9, has apertures 23 in order to permit volatilized iumigant to pass from the container into the atmosphere of the cabinet. The tablet can be made up by incorporating formaldehyde in a plaster of Paris tablet as in Ressler, U. S. Patent 1,408,535, or as in British Patent 17,464 of 1897.

In an upper opposite diagonal corner is an air circulator referred generally by the reference numeral 24 and containing a fan 25.

The fan and the heater are connected together electrically and under the control of a switch 26, which is so positioned and of such a, nature as to be operable and operated by the door ll. Thus, when the door I1 is in its closed position, the switch is closed and the heater and. fan operate. When the door is raised for access to the shelves, the switch is open and the heater and fan are disconnected from the current supply.

One of the major features of the device so far described is the spacing of the shelves throughout their periphery from the walls of the cabinet. This is particularly valuable because of the fact that the various articles placed upon the shelves for sterilization in many instances will close over so many of the perforations l5 as seriously to interfere with circulation of the fumigant. With these spaces around the edges of the shelves, this cannot happen.

Careful tests have been made of a device made in accordance with the above description and the results of these tests are indicated in the tables below. In each table, columns I are with the fan idle, columns II are with the fan operating, other conditions identical.

(1) B. anthracis (causative organism r thrax). Tooth brushes were used for this experiment. A three day old agar slant culture of 3., anthracis was washed with 5 ml. sterile physiological saline solution. The suspensio'fi' was-then heated to 80 C. for 30 minutes in order to destroy the vegetative cells. 0.3 ml. of sq ga a' was pipetted on each tooth brush. While the brushes were still damp, they were placedih the sterilizer for varying periods of time. Bacterial counts were then made on each tooth brush. The average of two counts is reported.

I I II II Time in Minutes Bacterial Percent Bacterial Percent Count Destroyed Count Destroyed (2) C1. welchii (causative organism of assedgrene). Experiment 1 was repeated using spores of Cl. Welchii. Anaerobic conditions of incubation were employed. The average of two counts is reported.

(3) Staphylococcus aureus. The experiment on brushes was repeated with a suspension of Staphylococcus aureus. do not produce spores, the suspension was not heated before the test.

I I II II Time in Minutes Bacterial Percent Bacterial Percent Count Destroyed Count Destroyed 41, 000 0 38, 000 O 38, OCH 8 300 47 30, 000 27 6; (1 83 27, 500 33 93 98 l1 200 73 0 100 780 98 4- 0 I00 (4) Streptococcus pyogenes. Experiment 3 was repeated with streptococcus pyogenes. Counts were made on blood plates.

I I II II Timein Minutes Bacterial Percent Bacterial. Percent Count Destroyed Count Destroyed 37,000 5 IS IOQ 65 12,200 or B, 100

n will be seen that the positive circulatlon oi the iumigant-air mixture has are "ariaible er f feet upon the efficiency of operation a theiievice.

Since these organisms 4 4 It will therefore be seen that I have provided a very effective and convenient apparatus for the purpose of disinfecting and sterilizing various articles.

In operation, the heater 22 and the fan 25 can be operated continuously if utilization of the cabinet is severe, that is, if the articles in the cabinet are being' constantly removed and replaced with others to be sterilized. In ordinary use, as in the average barber shop or beauty shop, usually it is only necessary to operate the heater over a short period of time during the morning and again during the afternoon; usually from five to ten minute's operation of the heater results in suiiicient vaporizationoi the formaldehyde to provide an atmosphere saturated with formaldehyde suflicient for the sterilization of many articles, even though the door is opened from time to time to remove and replace articles in the cabinet. The fan can be permitted to operate for a somewhat longer period of time to insure adequate circulation'"of the atmosphere over the articles to be sterilized. The heat from the vaporizer and the fan motor also raises the temperature of the cabinet atmosphere, making the latter more effective as a sterilizing medium and as a drying medium.

The cabinet is particularly economical in utilization of formaldehyde because of the provision of the sliding door. whichcan be moved from 0 closed to an open position and returned Without any particular disturbance of the atmosphere within the cabinet. As a result, the formaldehyde loss upon each opening and closing of the door is very slight.

I claim:

1. In a dry sterilizer, a cabinet of generally rectangular vertical section, an opening in a vertical side, channel members on each side of the opening, a. door sliding vertically in said channel members, a. plurality. of perforated. shelves hav-. ing their edges spaced from the sides of the cabinet 3 fumigant vaporizer in a lower corner and including an electric heater, an electric fan in an opposite upper corner, an electrical circuit for supplying current .to, the heater and. the fan, and a switch in thesaidciiicuil'. and ph sically located so as to be operable by the said door to close the circuit when said door is in its closed position.

2. In a dry sterilizer, a cabinet providing an enclosure and having a top and a bottom spaced apart with an intermediate shelf extending horizontally of said cabinet and providing only a limited restriction upon circulation of the atmosphere in the cabinet, a i igant vaporizer positioned in a lower corner oiiithe cabinet to vaporwe a -i'umigant vapor in the,cab'inet, and a fan in an upper'd iago'nal corner of the cabinet for forcing the atmosphere in the cabinet forcefully from th'top of the cabinet toward the bottom thereof.

3. In a dry sterilizer, a cabinet providing an enclosureand having a 'topand a bottom spaced apart with an intrrhediat sh'e'lf extending horizontally of said cabinet and providing only a limited restriction upon circulation of the atmosphere in the cabinet, said cabinet having a door slidable vertically to open and close the cabinet, a fumigant vaporizer positioned in a lower corner of the cabinet to vaporize a funiigant vapor in the cabinet, and a fan in an upper diagonal corner of the cabinet for forcing the atmosphere in the cabinet forcefully from the top of the cabinet toward the bottom thereof.

LEONARD FISHER.

N 0 references cited. 

